Space telephony.



L. DE FOREST.

' SPACETELEPHONY. APPLIOATION FILED JULY 8, 1907.

1,006,636, Patented 061211911.

UNI En STATES PAT NT OFFICE.

LEEIDE FOREST, OF NEW YORK, N. Y., ASSIGNOR TO DE FOREST RADIO TELEPHONE 00.,

' A CORPORATION OF NEW YORK.

SPACE TELEPHONY.

Specification of Letters Patent.

Application filed July 8, 1907. Serial No. 382,676.

To all whom it may concern:

Be it known that I, LEE DE FOREST, a citizen of the United States, and a resident ofNew York, in the county of New York and State of New York, have invented a new and useful Improvement in Space Telephony, of which the following is a specification.

My invention relates to space telephone transmitting systems, and its objects are to increase the distance over which transmission may take place and, in general, to improve the efliciency of such systems.

The drawings which accompany and form a part of this specification represent in diagram several arrangements of apparatus and circuits whereby said objects may be realized; but it will be understood that I do not limit myself specifically to the particular embodiments of my invention therein illustrated inasmuch as many modification's may be made both in the apparatus and in the circuit arrangements without departing from the principle of my invention.

In the drawings, Figures 1 and 2 represent space telephone transmitting systems constructed in accordance with the present invention.

In the figures, G is a source of electrical energy herein shown as a direct current generator.

R R are resistances or impedances.

C C. are condensers.

S S are dischargers for the condensers C C','and in the present instance are shown as gaps in which electric arcs may be created. Y

I, is the secondary of an oscillation transformer, of which the primaries are I and I T T T are transmitting devices which may be of any suitable construction and which are shown herein as microphones or variable resistance devices.

The circuits C S I and C S I, are oscillation circuits, each adapted to develop high frequency electrical oscillations having the same time period. cuits are initially designed and adjusted .to the same time period, and into step with each other and with the natural period of the antenna, and thereafter they naturally and automatically retain them condition of step or phase relation with respect to each other, ust as two alternating current generators, if adjusted to coincident These cirphase relation, when used to energize the same coil of a transformer, naturally tend to remain in step with each other. The oscillations developed by these circuits may have a spark-frequency higher than the more essential frequencies accompanying Patented Oct. 24, 1911.

articulate speech, or a spark-frequency higher than the limit of audibility, or as shown, eachcircuitmay be a continuously oscillating circuit or a singing-arc circuit of any approved type. Inasmuch as there is a limit to the amount of. energy that 'may shown as two, each associated in any suit-- able manner with a transmitting antenna V which maybe connected to earth at E through a plurality of branches. The number of said branches may be equal to the number of oscillation circuits employed, although I do not limit myself to this particular arrangement, and, inasmuch as there is a limit be employed with a singing-arc circuit, I employ a plurality of such circuits, herein to the amount of energy that may be passed through a telephone transmitting device, I employ a plurality of such devices, one for each of said branches. In this case, as will be obvious, the energy delivered by the oscil-' lation circuits to the antenna is divided into as'many portions as thereare branches to earth and each port-ion passes through a difi'erent one of the transmitting devices T T. I prefer as shown to connect'said transmitting devices in the earth connector of the antenna so that each will be at a pointhaving practically zero potential to earth. Controlling means common to saidtransmitting devices are provided, the controlling means shown in Fig. 1 consisting of the megaphone arrangement D whereby sound waves may be directed to both transmitters T T, and that shown in Fig. 2 consisting of the master transmitter T, which may be a microphone transmitter and which by varying the resistance of the circuit of the battery B causes the electromagnets F F to actuate the transmitters T T. I

I claim:

' 1. In a space telephone transmitting system, a transmitting antenna, a plurality of independent oscillation circuits having the same period associated therewith, a plurality of transmitting devices included in to all of said transmitting devices for simultaneously controlling the same.

2. In a space telephone transmitting system, a transmitting antenna, a plurahty of oscillation circuits associated therewith and having the same periods and adjusted to be v in step with each other, and cooperating to generate oscillations in the circuit of said antenna, a lurality of transmitting devices, each mcluded in circuit with the antenna, and operating to modify the oscillations therein, and means common to all of tem, a transmitting antenna, a plurality of oscillation circuits havin the same time period associated therewi and operatin to produce electrical oscillations in said antenna, a plurality of transmitting devices arranged in circuit with the antenna and at points having practically zero potential, and operating to modify the oscillations in said antenna, and means common to all of said transmitting devices for simultaneously controlling the same.

In testimony whereof, I have hereunto LEE DE FOREST.

Witnesses:

Roscoe KENT,

THOMAS I. GALLAGHER.

subscribed my name this 3d day of July 1907. 30 

